Humectant

Cysteine

Sulfur-containing amino acid with unique antioxidant properties — cysteine is a precursor to glutathione, the most important intracellular antioxidant. In hair products, it is responsible for the strength and elasticity of keratin bonds.

AntioxidantGlutathioneKeratin bondsHair

✓ Safe

Comedogenic Rating

0/5

Irritation Potential

0/5

What is it?

Cysteine (цистеїн, Cys) — conditionally essential amino acid with a thiol (-SH) group. In INCI: Cysteine. It is a precursor to glutathione — the main intracellular antioxidant. In keratin of hair and nails — it forms disulfide (-S-S-) bonds between polypeptide chains, providing mechanical strength.

Antioxidant and conditioning active in hair and skin products. Key component in keratin and bond-building procedures for hair. Also present in NMF complexes for skin.

Key Benefits

✦

Precursor to glutathione — master antioxidant

Cysteine is a limiting substrate for the synthesis of glutathione (GSH) in cells. GSH neutralizes free radicals, detoxifies heavy metals, and protects cellular components from oxidation — especially important under UV exposure and pollution.

◈

Disulfide bonds and hair strength

Disulfide (-S-S-) bonds between cysteine residues of keratin determine the structure and strength of the hair shaft. Topical cysteine supports the restoration of disulfide bonds after damage (chemical perm, bleaching, thermal exposure).

✧

Antioxidant protection of the skin

The free thiol group of cysteine directly reacts with reactive oxygen species. In synergy with methionine and vitamin E, it provides comprehensive protection against oxidative stress.

Suitable for

Damaged hairSkin under stressMature skinAll skin types

Main Actions

✓ Precursor to glutathione✓ Antioxidant✓ Restoration of keratin bonds

CategoryHumectants

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